Recently, flat panel displays (FPD) have become popular due to their smaller footprint and larger, flatter screen compared to conventional technology. For example, liquid crystal displays (LCD) and plasma display panels (PDP) are replacing cathode ray tubes (CRT) in many domestic applications. However, some types of FPD technology have disadvantages compared to conventional CRT technology. For example, LCDs have a slow response rate, which degrades the quality of fast-moving images, and PDPs have a reduced life expectancy.
An alternative technology to LCD or PDP is a field emission display (FED). A typical FED incorporates a large array of fine metal tips or carbon nano-tubes (CNT), which emit electrons through a process known as field emission. The array of electron emitters lies behind a phosphor coated screen, which, similar to a CRT, emits light when the electrons strike.
There are many challenges to the commercial fabrication of such devices. The use of CNT electron emitters, for example, may improve the potential performance of FEDs but adds further complexity to the fabrication process.
United States Patent publication number 2006/0046602 discloses a method of manufacturing a field emitter electrode using self-assembling carbon nanotubes as well as a field emitter electrode manufactured thereby. The method comprises anodizing an aluminum substrate to form an anodized aluminum oxide film having a plurality of uniform pores on the aluminum substrate, preparing an electrolyte solution having carbon nano-tubes dispersed therein, immersing the anodized aluminum substrate in the electrolyte solution and applying a given voltage to the aluminum substrate as one electrode, so as to attach the carbon nano-tubes to the pores, and fixing the attached carbon nano-tubes to the pores. The suggested application is as a back light for an LCD, and a gate electrode is not disclosed.
The emitter current for those prior art devices above can be quite high, which reduces the life expectancy. Also, the CNT for those prior art devices above are longer than the depth of the pore. In other words, the tips of the CNT are exposed from the pores. It would be desirable therefore to provide an electron emitter array which has a fast response, a long lifetime, an uniformity and/or a high luminous intensity and/or improved methods of fabrication.